Pass DO_FOR_EACH_INCLUDE_BROKEN when iterating over replacement refs
so that the iteration does not require opening the named objects from
the object store. This avoids a dependency cycle between object access
and replace ref iteration.

Moreover the ref subsystem has not been migrated yet to access the
object store via passed in repository objects.  As a result, without
this patch, iterating over replace refs in a repository other than
the_repository it produces errors:

   error: refs/replace/3afabef75c627b894cccc3bcae86837abc7c32fe does not point to a valid object!

Noticed while adapting the object store (and in particular its
evaluation of replace refs) to handle arbitrary repositories.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The philosophy of reference locking has been, "if another process is
changing a reference, then whatever I'm trying to do to it will
probably fail anyway because my old-SHA-1 value is probably no longer
current". But this argument falls down if the other process has locked
the reference to do something that doesn't actually change the value
of the reference, such as `pack-refs` or `reflog expire`. There
actually *is* a decent chance that a planned reference update will
still be able to go through after the other process has released the
lock.

So when trying to lock an individual reference (e.g., when creating
"refs/heads/master.lock"), if it is already locked, then retry the
lock acquisition for approximately 100 ms before giving up. This
should eliminate some unnecessary lock conflicts without wasting a lot
of time.

Add a configuration setting, `core.filesRefLockTimeout`, to allow this
setting to be tweaked.

Note: the function `get_files_ref_lock_timeout_ms()` cannot be private
to the files backend because it is also used by `write_pseudoref()`
and `delete_pseudoref()`, which are defined in `refs.c` so that they
can be used by other reference backends.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is shorter, makes the logic a bit easier to follow, and is
perhaps a bit faster too.

The logic is to make the final decision only when "subject" is there,
its early part matches "match", and the match is at the slash
boundary (or the whole thing).
Signed-off-by: NChristian Couder <chriscool@tuxfamily.org>
Reviewed-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert the flags for get_oid_with_context and friends to use "OID"
instead of "SHA1" in their names.

This transform was made by running the following one-liner on the
affected files:

  perl -pi -e 's/GET_SHA1/GET_OID/g'
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When using the hashmap a common need is to have access to caller provided
data in the compare function. A couple of times we abuse the keydata field
to pass in the data needed. This happens for example in patch-ids.c.

This patch changes the function signature of the compare function
to have one more void pointer available. The pointer given for each
invocation of the compare function must be defined in the init function
of the hashmap and is just passed through.

Documentation of this new feature is deferred to a later patch.
This is a rather mechanical conversion, just adding the new pass-through
parameter.  However while at it improve the naming of the fields of all
compare functions used by hashmaps by ensuring unused parameters are
prefixed with 'unused_' and naming the parameters what they are (instead
of 'unused' make it 'unused_keydata').
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Remove the unused wildopts placeholder struct from being passed to all
wildmatch() invocations, or rather remove all the boilerplate NULL
parameters.

This parameter was added back in commit 9b3497ca ("wildmatch: rename
constants and update prototype", 2013-01-01) as a placeholder for
future use. Over 4 years later nothing has made use of it, let's just
remove it. It can be added in the future if we find some reason to
start using such a parameter.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Now that the interface between `files_ref_store` and
`packed_ref_store` is relatively narrow, move the latter into a new
module, "refs/packed-backend.h" and "refs/packed-backend.c". It still
doesn't quite implement the `ref_store` interface, but it will soon.

This commit moves code around and adjusts its visibility, but doesn't
change anything.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

`for_each_bisect_ref()` is called by `for_each_bad_bisect_ref()` with
a term "bad". This used to make it call `for_each_ref_in_submodule()`
with a prefix "refs/bisect/bad". But the latter is the name of the
reference that is being sought, so the empty string was being passed
to the callback as the trimmed refname. Moreover, this questionable
practice was turned into an error by

    b9c8e7f2 prefix_ref_iterator: don't trim too much, 2017-05-22

It makes more sense (and agrees better with the documentation of
`--bisect`) for the callers to receive the full reference names. So

* Add a new function, `for_each_fullref_in_submodule()`, to the refs
  API. This plugs a gap in the existing functionality, analogous to
  `for_each_fullref_in()` but accepting a `submodule` argument.

* Change `for_each_bad_bisect_ref()` to call the new function rather
  than `for_each_ref_in_submodule()`.

* Add a test.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Stop including config.h by default in cache.h.  Instead only include
config.h in those files which require use of the config system.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Instead of handling `GIT_REF_PARANOIA` in
`files_ref_iterator_begin()`, handle it in
`refs_ref_iterator_begin()`, where it will cover all reference stores.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It's pretty cheap to make sure that the caller didn't pass us an
unsorted list by accident, so do so.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Eliminate a theoretical risk of integer overflow if the two types have
different sizes.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It will soon have some other users.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In the future, compound reference stores will sometimes need to modify
references in two different reference stores at the same time, meaning
that a single logical reference transaction might have to be
implemented as two internal sub-transactions. They won't want to call
`ref_transaction_commit()` for the two sub-transactions one after the
other, because that wouldn't be atomic (the first commit could succeed
and the second one fail). Instead, they will want to prepare both
sub-transactions (i.e., obtain any necessary locks and do any
pre-checks), and only if both prepare steps succeed, then commit both
sub-transactions.

Start preparing for that day by adding a new, optional
`ref_transaction_prepare()` step to the reference transaction
sequence, which obtains the locks and does any prechecks, reporting
any errors that occur. Also add a `ref_transaction_abort()` function
that can be used to abort a sub-transaction even if it has already
been prepared.

That is on the side of the public-facing API. On the side of the
`ref_store` VTABLE, get rid of `transaction_commit` and instead add
methods `transaction_prepare`, `transaction_finish`, and
`transaction_abort`. A `ref_transaction_commit()` now basically calls
methods `transaction_prepare` then `transaction_finish`.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Move the check that `transaction->state` is valid from
`files_transaction_commit()` to `ref_transaction_commit()`, where
other future reference backends can benefit from it as well.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Just because the files backend can't retain reflogs for deleted
references is no reason that they shouldn't be supported by the
virtual method interface. Also, `delete_ref()` and `refs_delete_ref()`
have already gained `msg` parameters. Now let's add them to
`delete_refs()` and `refs_delete_refs()`.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Eliminate any chance of integer overflow on platforms where the two
types have different sizes.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The backend already correctly restricts its output to references whose
names start with the prefix. By passing the prefix again to
`prefix_ref_iterator`, we were forcing that iterator to do redundant
prefix comparisons. So set it to the empty string.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert struct ref_array_item to use struct object_id by changing the
definition and applying the following semantic patch, plus the standard
object_id transforms:

@@
struct ref_update E1;
@@
- E1.new_sha1
+ E1.new_oid.hash

@@
struct ref_update *E1;
@@
- E1->new_sha1
+ E1->new_oid.hash

@@
struct ref_update E1;
@@
- E1.old_sha1
+ E1.old_oid.hash

@@
struct ref_update *E1;
@@
- E1->old_sha1
+ E1->old_oid.hash

This transformation allows us to convert write_ref_to_lockfile, which is
required to convert parse_object.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Git's source code assumes that unsigned long is at least as precise as
time_t. Which is incorrect, and causes a lot of problems, in particular
where unsigned long is only 32-bit (notably on Windows, even in 64-bit
versions).

So let's just use a more appropriate data type instead. In preparation
for this, we introduce the new `timestamp_t` data type.

By necessity, this is a very, very large patch, as it has to replace all
timestamps' data type in one go.

As we will use a data type that is not necessarily identical to `time_t`,
we need to be very careful to use `time_t` whenever we interact with the
system functions, and `timestamp_t` everywhere else.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

files-backend at this point is still aware of the per-repo/worktree
separation in refs, so it can handle a linked worktree.

Some refs operations are known not working when current files-backend is
used in a linked worktree (e.g. reflog). Tests will be written when
refs_* functions start to be called with worktree backend to verify that
they work as expected.

Note: accessing a worktree of a submodule remains unaddressed. Perhaps
after get_worktrees() can access submodule (or rather a new function
get_submodule_worktrees(), that lists worktrees of a submodule), we can
update this function to work with submodules as well.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It turns out that we can now implement
`refs_verify_refname_available()` based on the other virtual
functions, so there is no need for it to be defined at the backend
level. Instead, define it once in `refs.c` and remove the
`files_backend` definition.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This removes the "submodule" from submodule_hash_entry and other
function names. The goal is to reuse the same code and data structure
for other ref store types. The first one is worktree ref stores.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

As documented in git-receive-pack(1), updating a ref from
within the pre-receive hook is dangerous and can corrupt
your repo. This patch forbids ref updates entirely during
the hook to make it harder for adventurous hook writers to
shoot themselves in the foot.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Extract a new function from `do_for_each_ref()`. It will be useful
elsewhere.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Extract a new function from `refs_resolve_ref_unsafe()`. It will be
useful elsewhere.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It only has one caller, not worth keeping just for convenience.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The transaction struct now takes a ref store at creation and will
operate on that ref store alone.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is not meant to cover all existing API. It adds enough to test ref
stores with the new test program test-ref-store, coming soon and to be
used by files-backend.c.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This function is intended to replace *_submodule() refs API. It provides
a ref store for a specific submodule, which can be operated on by a new
set of refs API.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

files-backend.c is unlearning submodules. Instead of having a specific
check for submodules to see what operation is allowed, files backend
now takes a set of flags at init. Each operation will check if the
required flags is present before performing.

For now we have four flags: read, write and odb access. Main ref store
has all flags, obviously, while submodule stores are read-only and have
access to odb (*).

The "main" flag stays because many functions in the backend calls
frontend ones without a ref store, so these functions always target the
main ref store. Ideally the flag should be gone after ref-store-aware
api is in place and used by backends.

(*) Submodule code needs for_each_ref. Try take REF_STORE_ODB flag
out. At least t3404 would fail. The "have access to odb" in submodule is
a bit hacky since we don't know from he whether add_submodule_odb() has
been called.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Like the previous commit, we'd like to avoid the assumption
that refs fit into PATH_MAX-sized buffers. These callsites
have an extra twist, though: they write the refnames using
mksnpath. This does two things beyond a regular snprintf:

  1. It quietly writes "/bad-path/" when truncation occurs.
     This saves the caller having to check the error code,
     but if you aren't actually feeding the result to a
     system call (and we aren't here), it's questionable.

  2. It calls cleanup_path(), which removes leading
     instances of "./".  That's questionable when dealing
     with refnames, as we could silently canonicalize a
     syntactically bogus refname into a valid one.

Let's convert each case to use a strbuf. This is preferable
to xstrfmt() because we can reuse the same buffer as we
loop.
Signed-off-by: NJeff King <peff@peff.net>

files-backend is now initialized with a $GIT_DIR. Converting a submodule
path to where real submodule gitdir is located is done in get_ref_store().

This gives a slight performance improvement for submodules since we
don't convert submodule path to gitdir at every backend call like
before. We pay that once at ref-store creation.

More cleanup in files_downcast() and files_assert_main_repository()
follows shortly. It's separate to keep noises from this patch.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

get_ref_store() will soon be renamed to get_submodule_ref_store().
Together with future get_worktree_ref_store(), the three functions
provide an appropriate ref store for different operation modes. New APIs
will be added to operate directly on ref stores.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is the last function in this code (besides public API) that takes
submodule argument and handles both main/submodule cases. Break it down,
move main store registration in get_main_ref_store() and keep the rest
in register_submodule_ref_store().
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This helps the future changes in this code. And because get_ref_store()
is destined to become get_submodule_ref_store(), the "get main store"
code path will be removed eventually. After this the patch to delete
that code will be cleaner.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

With get_main_ref_store() being used inside get_ref_store(),
lookup_ref_store() is only used for submodule code path. Rename to
reflect that and delete dead code.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This eliminates three magic numbers.
Signed-off-by: NSZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>